Creating JSON data in Javascript

Quick post about how to create JSON data in javascript.
I want to POST some inputs via AJAX but I want send them just in one variable, don't ask me why. I just want to do it that way.

here is my HTML code

<input id="name" type="text">

<input id="phone" type="text">

<input id="address" type="text">

I want send them as JSON data, here is how I do it:

var obj = new Object();
obj.name = document.getElementById('name').value;
obj.phone= document.getElementById('phone').value;
obj.address= document.getElementById('address').value;

var myData = JSON.stringify(obj);

That's it. the variable myData is the json data.